WC Apparatus for Rail Vehicles

ABSTRACT

A WC apparatus for rail vehicles is provided. The WC apparatus includes a flushing liquid tank, a toilet and a collecting tank. Further, the apparatus has control device which automatically initiates discharges of doses of disinfectants and/or calcification inhibitors into flushing water in order to keep a pH value below an associated threshold value.

FIELD OF INVENTION

The invention relates to a WC apparatus, having a flushing liquid tank,a toilet and a collecting tank, as used in rail vehicles, for example.

SUMMARY OF INVENTION

In a WC apparatus in transport engineering (rail, aircraft) with andwithout the addition of pH-acidic and pH-neutral biocidic disinfectantsin the flushing water, it is sometimes possible for limescale and urinescale deposits to arise in the WC apparatus which can significantlyimpair functionality and result in total failure.

The procedure for removing deposits, such as limescale and/or urinescale, in WC apparatuses is to periodically perform tortuous cleaning ofthe WC apparatuses with decalcifiers. This means very significantmaintenance involvement.

There is a relationship between the pH value of the flushing liquid, theamount of urine and feces introduced and the tendency towardcalcification and urine scale formation in the waste water system of theWC apparatus. Within a particular range, above a limit value, anyincrease in the pH value increases the risk of urine scale and limescaledeposits forming in the waste water system.

Against this background, the invention is based on the object ofpresenting a WC apparatus also for use in rail vehicles which is moremaintenance-friendly in terms of avoiding calcification and ensuring thedisinfecting action.

This object is achieved in the WC apparatus cited at the outset byvirtue of a control device being provided which automatically initiatesdischarges of doses of disinfectants and/or calcification inhibitorsinto the flushing water in order to keep the pH value below anassociated threshold value.

In this case, the control device of such a WC apparatus can be operatedin regulated or else unregulated form.

In the case of regulated operation of the control device, said controldevice can monitor a profile of the pH value and, when the associatedthreshold value is exceeded, initiate the discharges of disinfectantsand/or calcification inhibitors into the flushing water, wherein thecontrol device has a connection for signaling purposes to at least onesensor for the pH value in order to monitor the pH value.

On account of the typically continuous monitoring of the profile of thepH value, it becomes possible to tell when measures to reduce the pHvalue need to be taken. In this context, one or more threshold valuesmay be defined which initiate discharge of disinfectants and/orcalcification inhibitors.

A first pH threshold value may be between 6 and 7, preferably 6.3, andthe control device can discharge calcification inhibitors into theflushing water when this threshold value is exceeded. The choice of thefirst pH threshold value is based on empirical examinations by theinventors.

The same also applies to a second pH threshold value, which may be 8.0.Whenever this threshold value is exceeded, the control device dischargesdisinfectants into the flushing water, so that the disinfecting actionis ensured.

In respect of maintaining an adequate disinfecting action, provision maybe made for the control device to monitor a time profile of the pH valueand, when a threshold value for a pH value increase is exceeded, toinitiate discharge of additional disinfectant into the flushing water.In this respect, there are two alternative procedures available forprompting the discharge of additional disinfectant into the flushingwater. With regard to the pH value increase, it may be necessary toconsider a change in the pH value of one unit per hour to be abenchmark.

Preferably, the control device is of adaptive design and it optimizesrespective doses of disinfectants and/or calcification inhibitors fordischarge into the flushing water, on the basis of the profile of the pHvalue. By way of example, it is possible for the control device todischarge various doses of calcification inhibitors into the flushingwater, and at the same time to monitor the time profile of the pH value,when the threshold value of 6.3 for the pH value is exceeded. It is thenpossible to detect a dependency of the pH value profile on the metereddose of calcification inhibitor. The result will then be that an optimumdose of calcification inhibitor is found which effectively lowers the pHvalue below the threshold value of 6.3. In this case, the control deviceis able to minimize the period for which the threshold value is exceededfor the purpose of optimization.

There is a plurality of alternatives for discharging the doses ofdisinfectants and/or calcification inhibitors. Said discharge may bedirectly into a flushing line or else directly into the toilet, forexample.

The WC apparatus may also be provided with a control device in which noactive regulation takes place, but instead the aims of this inventionare achieved automatically in another way. By way of example, thecontrol device can initiate the discharge of the doses of disinfectantsand/or calcification inhibitors on the basis of detection of a degree ofuse of the WC apparatus. This means that after the WC flushing apparatushas been operated a number n of times, the discharges to which referencehas been made take place automatically, for example. Alternatively,provision may be made for the control device to have a timer which ituses to initiate the discharge of the doses of disinfectants and/orcalcification inhibitors into the flushing water at fixed intervals oftime. The illustrated alternatives are therefore based either on use oron time, so that the pH value is kept in a suitable range without theuse of any kind of sensors.

During unregulated operation, the control device can discharge firmlyset doses of disinfectants and/or calcification inhibitors. The pHthreshold value may be between 6 and 7.

In other words, use-dependent or time-interval-controlleddischarge—without checking the pH value by means of a sensor—ofdisinfectants and/or calcification inhibitors could take place over theperiod of use of the WC installation.

BRIEF DESCRIPTION OF THE DRAWINGS

An exemplary embodiment of the invention is explained in more detailbelow with reference to the drawing. The single FIGURE shows a schematicblock diagram illustration of a WC apparatus.

DETAILED DESCRIPTION OF INVENTION

The WC apparatus shown has a flushing liquid tank 1, the flushing liquidin which is used to purge feces from a toilet 2. Purged feces are routedto a collecting tank 3.

The flushing liquid tank 1 is connected by means of respective valves 4,5 both to a reservoir 6 containing calcification inhibitors and to areservoir 7 containing disinfectants.

The effect intended to be achieved in the WC apparatus is now thatcalcification is reduced and a required degree of disinfection isensured. For this purpose, a pH value in the WC apparatus iscontinuously monitored. In the present exemplary embodiment, two pHvalue sensors 8, 9 are provided, one of which is arranged within theline connection between toilet 2 and collecting tank 3 and the other ofwhich is arranged within the collecting tank 3.

A control device 10 is connected for signaling purposes to the pH valuesensors 8, 9 and, on the basis of recorded measured values, forms arepresentative pH value which can then be compared with thresholdvalues. In this case, a first pH threshold value is 6.3. When it isexceeded, this prompts the control device 10 to actuate the valve 4 suchthat a suitable dose of calcification inhibitor is discharged from thereservoir 6 into the flushing liquid tank 1. Besides the calcificationinhibitors, it is additionally alternatively possible to dischargecomplexing agents, such as citric acid.

When the pH value of approximately 8.0 is exceeded, there is the riskthat the disinfecting action is no longer adequate. If this thresholdvalue is exceeded, or the pH value increases significantly over acertain period, the control device 10 prompts the discharge of asuitable dose of disinfectants from the reservoir 7 into the flushingliquid tank 1, specifically by opening the valve 5. Alternatively, thedischarge may also be directly into the flushing line or the toilet 2.This applies to all modes of operation of the control device 10.

The control device 10 is of adaptive design, i.e. it is capable ofdischarging various doses of disinfectants and/or calcificationinhibitors/complexing agents into the flushing liquid tank 1 and at thesame time of observing the time profile of the pH value. In this way, itis possible to optimize the doses at which the prescribed thresholdvalues remain reliably undershot.

The invention can be used both for recirculating WC apparatuses—this isindicated by means of a dashed line in the FIGURE—or else tononrecirculating WC apparatuses, as are used for WC apparatuses in theleisure/camping sector and in the commercial sector, for example.

Unregulated operation of the control device 10 is performed such thatthe control device 10 discharges a firmly set volume of disinfectantsand/or calcification inhibitors into the flushing liquid tank 1 ordirectly into the line for the flushing liquid before the toilet 2 at aninterval of time or after the WC apparatus has been used. This resultsin essentially the same design as that shown in the FIGURE. Only thesensors 8, 9 and their supply lines are missing. Instead, the controldevice 10 has a timer or means for detecting a degree of use of the WCapparatus.

1.-15. (canceled)
 16. A WC (water closet) apparatus, comprising: aflushing liquid tank; a toilet; a collecting tank; and a control devicewhich automatically initiates discharges of doses of disinfectantsand/or calcification inhibitors into flushing water in order to keep apH value below an associated threshold value.
 17. The WC apparatus asclaimed in claim 16, wherein the control device monitors a profile ofthe pH value and, when the associated threshold value is exceeded,initiates the discharges of disinfectants and/or calcificationinhibitors into the flushing water.
 18. The WC apparatus as claimed inclaim 17, further comprising: a sensor connected to the control device,the sensor measuring the pH value and transmitting the pH value to thecontrol device.
 19. The WC apparatus as claimed in claim 17, wherein afirst pH threshold value is between 6 and 7 and the control devicedischarges calcification inhibitors into the flushing water when thefirst threshold value is exceeded.
 20. The WC apparatus as claimed inclaim 17, wherein a second pH threshold value is 8.0 and the controldevice discharges disinfectants into the flushing water when the secondthreshold value is exceeded.
 21. The WC apparatus as claimed in claim19, wherein a second pH threshold value is 8.0 and the control devicedischarges disinfectants into the flushing water when the secondthreshold value is exceeded.
 22. The WC apparatus as claimed in claim16, wherein the control device monitors a time profile of the pH valueand, when a threshold value for a pH value increase is exceeded,initiates discharge of additional disinfectant into the flushing water.23. The WC apparatus as claimed in claim 17, wherein the control deviceis configured to adapt and optimize respective doses of disinfectantsand/or calcification inhibitors for discharge into the flushing water onthe basis of the profile of the pH value.
 24. The WC apparatus asclaimed in claim 23, wherein the control device is configured tominimize a period for which the threshold value is exceeded for thepurpose of optimization.
 25. The WC apparatus as claimed in claim 18,wherein the sensor is arranged in the collecting tank.
 26. The WCapparatus as claimed in claim 25, wherein a further sensor is arrangedupstream of the collecting tank.
 27. The WC apparatus as claimed inclaim 18, wherein a further sensor is arranged upstream of thecollecting tank.
 28. The WC apparatus as claimed in claim 16, whereinthe doses of disinfectants and/or calcification inhibitors aredischarged directly into a flushing line.
 29. The WC apparatus asclaimed in claim 16, wherein the doses of disinfectants and/orcalcification inhibitors are discharged directly into the toilet. 30.The WC apparatus as claimed in claim 16, wherein the control device isconfigured to initiate the discharges of the doses of disinfectantsand/or calcification inhibitors based upon a degree of use of the WCapparatus.
 31. The WC apparatus as claimed in claim 16, wherein thecontrol device includes a timer for initiating the discharge of thedoses of disinfectants and/or calcification inhibitors into the flushingwater at fixed intervals of time.
 32. The WC apparatus as claimed inclaim 30, wherein the control device discharges firmly set doses ofdisinfectants and/or calcification inhibitors.
 33. The WC apparatus asclaimed in claim 31, wherein the control device discharges firmly setdoses of disinfectants and/or calcification inhibitors.